U.S. patent application number 11/579358 was filed with the patent office on 2009-01-01 for method for controlling an automatic transmission.
Invention is credited to Ramon Cordt, Peter Herter, Thomas Jager, Mario Steinborn, Andelko Vesenjak, Norbert Wiencek.
Application Number | 20090005942 11/579358 |
Document ID | / |
Family ID | 34965001 |
Filed Date | 2009-01-01 |
United States Patent
Application |
20090005942 |
Kind Code |
A1 |
Wiencek; Norbert ; et
al. |
January 1, 2009 |
Method for Controlling an Automatic Transmission
Abstract
An automatic transmission control method in which at least one
of a starting clutch, a clutch coupling and transmission elements,
for selection as well as engagement and disengagement of a gear
step, are determined as a function of respectively existing
variables representing the driving situation as well as the
driver's wishes can be activated by actuators which are controlled
by a control and regulation device. The method comprising the steps
of collecting and normalizing the input variable into standard
input variables; weighting with weighting factors and summarizing;
converting the weighted input variables into intermediate
variables; selecting a specific range of values which represents a
specific shifting sequence; and implementing the shifting
operation.
Inventors: |
Wiencek; Norbert; (Hagnau,
DE) ; Vesenjak; Andelko; (Meckenbeuren, DE) ;
Jager; Thomas; (Meckenbeuren, DE) ; Steinborn;
Mario; (Friedrichshafen, DE) ; Cordt; Ramon;
(Friedrichshafen, DE) ; Herter; Peter;
(Ravensburg, DE) |
Correspondence
Address: |
DAVIS BUJOLD & Daniels, P.L.L.C.
112 PLEASANT STREET
CONCORD
NH
03301
US
|
Family ID: |
34965001 |
Appl. No.: |
11/579358 |
Filed: |
April 28, 2005 |
PCT Filed: |
April 28, 2005 |
PCT NO: |
PCT/EP2005/004532 |
371 Date: |
August 25, 2008 |
Current U.S.
Class: |
701/58 |
Current CPC
Class: |
F16H 2059/003 20130101;
F16H 2302/04 20130101; F16H 61/02 20130101 |
Class at
Publication: |
701/58 |
International
Class: |
F16H 61/02 20060101
F16H061/02 |
Foreign Application Data
Date |
Code |
Application Number |
May 3, 2004 |
DE |
102004021801.3 |
Claims
1-8. (canceled)
9. A method for controlling an automatic transmission, in which at
least one of a starting clutch, a clutch coupling and transmission
elements for selection as well as engagement and disengagement of a
gear step are determined as a function of respectively existing
variables representing a driving situation as well as a wish of a
driver can be activated by actuators which are controlled by a
control and regulation device, the method comprising the steps of:
collecting input variables for a shifting operation; normalizing
the input variable into standard input variables; weighting of the
standardized input variables with weighting factors; summarizing
the standardized and weighted input variables, one of summarizing
and multiplying of the norms and weighted input variables into
intermediate variables; classifying the intermediate variables into
at least one specific range of values which represents a specific
shifting sequence; and implementation of the shifting operation
through recognition of the actuator with the assistance of an
acquired type of shifting sequence of at least one of assigned
actuator control variables and regulation algorithms.
10. A method for controlling an automatic transmission, in which at
least one of a starting clutch, a clutch coupling and transmission
elements for selection as well as engagement and disengagement of a
gear step are determined as a function of respectively existing
variables representing a driving situation as well as a wish of a
driver can be activated by actuators which are controlled by a
control and regulation device, the method comprising the steps of:
recording of interacting input variables of the shifting operation;
normalizing the input variables into a standard input variables;
weighting of the standardized input variables with weighting
factors, summarization of the standardized and weighted input
variables; at least one of summarizing and multiplying the norms
and weighted input variables into intermediate variables; utilizing
the intermediate variables as variation factors, whose actuator
control variables and/or regulator algorithms is associated to at
least one of the actuators, implementation of the shifting
operation through recognition of at least one of the actuators with
the assistance of variation factors of adapted actuator control
variables and/or regulation programs.
11. The method according to claim 9, further comprising the step of
one of recording and determining as input variables, one of
additively and alternatively, at least one of: an accelerator
adjustment angle; an operating situation on a kick-down-switch on a
pedal; a brake activation signal for a current position of a
service brake of the vehicle; one of a vehicle speed and a variable
equivalent to vehicle speed; a longitudinal acceleration of the
vehicle; a lateral acceleration of the vehicle; a driving
resistance; a gradient angle of a roadway; a current gear being
utilized; a target gear for a present driving condition; a current
engine torque of a vehicle transmission; a clutch temperature as an
indicator of thermal stress conditions of the clutch; and a current
mass of the vehicle.
12. The method according to claim 10, further comprising the step
of one of recording and determining as input variables, one of
additively and alternatively, at least one of: an accelerator
adjustment angle; an operating situation on a kick-down-switch on a
pedal; a brake activation signal for a current position of a
service brake of the vehicle; one of a vehicle speed and a variable
equivalent to vehicle speed; a longitudinal acceleration of the
vehicle; a lateral acceleration of the vehicle; a driving
resistance; a gradient angle of a roadway; a current gear being
utilized; a target gear for a present driving condition; a current
engine torque of a vehicle transmission; a clutch temperature as an
indicator of thermal stress conditions of the clutch; and a current
mass of the vehicle.
13. The method according to claim 9, further comprising the step of
using, as the weighting factors, variables that characterize at
least one of: a type of the vehicle; a type of the transmission;
performance characteristics of a drive motor; and a construction of
the drive train.
14. The method according to claim 10, further comprising the step
of using, as the weighting factors, variables that characterize at
least one of: a type of the vehicle; a type of the transmission;
performance characteristics of a drive motor; and a construction of
the drive train.
15. The method in accordance with claim 13, further comprising the
step of considering, with at least one weighting factor, whether
the transmission is in a passenger vehicle, in a truck and in some
other commercial vehicle.
16. The method in accordance with claim 14, further comprising the
step of considering, with at least one weighting factor, whether
the transmission is in a passenger vehicle, in a truck and in some
other commercial vehicle.
17. The method according to claim 15, further comprising the step
of considering, with at least one weighting factor, whether the
commercial vehicle is a long distance transport vehicle, a city
delivery vehicle, a travel bus and a cross-country vehicle.
18. The method according to claim 15, further comprising the step
of considering, with at least one weighting factor, whether the
commercial vehicle is a long distance transport vehicle, a city
delivery vehicle, a travel bus and a cross-country vehicle.
19. The method according to claim 17, further comprising the step
of multiplying the weighting factors by a respectively assigned
standardized input variable.
20. The method according to claim 18, further comprising the step
of multiplying the weighting factors by a respectively assigned
standardized input variable.
21. The method according to claim 9, further comprising the step of
choosing limits of the classification ranges for determination of
the shifting sequence depending on at least one of a type of the
motor vehicle, the transmission, the performance characteristics of
the drive motor and the construction of the drive train.
22. The method according to claim 10, further comprising the step
of choosing limits of the classification ranges for determination
of the shifting sequence depending on at least one of a type of the
motor vehicle, the transmission, the performance characteristics of
the drive motor and the construction of the drive train.
Description
[0001] This application is a national stage completion of
PTC/EP2005/004532 files Apr. 28, 2005 which claims priority from
German Application Serial No. 10 2004 021 801.3 filed May 3,
2004.
FIELD OF THE INVENTION
[0002] The application concerns a control method of an automatic
transmission.
BACKGROUND OF THE INVENTION
[0003] Automatic transmissions have been used in various types of
vehicles for a fairly long period of time. As is known, such
automatic transmissions have favored the operation of a starting
clutch and a clutch coupling, as well as the assortments of switch
valves and the engagement and the disengagement of gears is made
possible with the help of hydraulic actuators which were developed
as piston-cylinder arrangements. On the other hand, there are
vehicles in existence that only rely upon a starting clutch or a
clutch coupling or on those elements of the transmission that are
purely essential. Activation of the aforementioned actuator is
controlled by the transmission gearbox with the aid of control and
regulating programs, based on information about the driving
situation, the shifting situation as well as the desired
performance of the vehicle operator in relation to the clutch and
the shift options.
[0004] Even if these transmissions, compared to other types of
automatic transmissions such as continuous variable transmissions
or conventional stepped automatic transmissions using planetary
gears, are simple in construction and relatively inexpensive, these
automatic gearboxes exhibit an interruption in traction during
shifting operations, which the operator or passengers of the
vehicles in particular can experience as uncomfortable. The
interruption of traction with the use of these types of automatic
transmissions in commercial vehicles, however, can also prove to be
disadvantageous or at least as having a diminished comfort when,
for example, a truck with a heavy load at an intersection can only
execute a very slow starting process.
[0005] Those skilled in the art know that a gear ratio change
sequence in an automatic transmission can be roughly subdivided
into three phases. For a motor vehicle proceeding in a driving
state, first there is the gear disconnection of the gear step
previously utilized, as well as disengagement of the starting
clutch and the clutch coupling, through which the torque transfer
from the motor to the transmission is interrupted. Following this
is the selection of the new gear position for shifting and, as the
case may be, engagement of the necessary transmission elements for
the new transmission gear after which the coupling is engaged and a
new load build up follows.
[0006] For all of these shifting phases, the torque of the vehicle
is influence deviated from the real wishes of the driver, who
obviously wishes a forward creep free of any tractive force
interruption. The primary goal of a person skilled in the art of
the development of transmissions is, therefore, to attain as
quickly as possible the necessary shifting intervals for each of
these phases. In contrast, a very short shifting causes a
diminution of the shifting comfort as well as stronger mechanical
stress on the transmission components involved in the shifting
process through an associated rapid change in torque. For these
mentioned reasons, the actually realized shifting time in an
automatic transmission is always a compromise between conflicting
interests relevant to the shortest possible shifting time, the
highest possible shifting comfort as well as the lowest possible
component stresses.
[0007] The invention is based upon the knowledge that a portion of
the factors influencing actual shifting time are not constant but
rather are a function of the respective driving situation, the
individual motor vehicle configuration for a specified vehicle
type, as well as different driving preferences regarding the
comfort and the speed of shifting.
[0008] Purely theoretically, a number of combinations to be applied
arise from the variables influencing the optimal shifting sequence
which can no longer be meaningfully controlled by a control and
regulatory program in this regard, which would ultimately lead to
many different shifting operations with individual shifting times,
component loads and shifting comfort.
[0009] Moreover, a desire exists on the part of manufacturers of
automated transmissions from the point of view of cost-savings of
developing a uniform control and regulation program for all these
types of transmissions which takes into consideration the
respective motor vehicle type, its manner of use, as well as the
individual driving conditions and the driving preferences.
[0010] Against this background, the invention is based upon the
objective of presenting a method for controlling an automatic
transmission with which, as a function of the mentioned influencing
factors, such as possibly the driving conditions, the vehicle
configuration and the performance wish of the operator, where a
shifting operation which is appropriate to the situation and
optimal with regards to its duration, shifting comfort and the
individual component stresses can be implemented with an automatic
transmission. Moreover, this method should be suited for being used
without major changes in the transmission gearbox for various types
of automatic gearboxes.
SUMMARY OF THE INVENTION
[0011] The invention is based on the fundamental idea that only a
few types of shifting sequences can be constructed, based on a
multitude of variables determining or influencing the shifting
process which, in this regard, determine the duration of the shift,
the shifting comfort and the stress upon the individual components
associated with the gear ratio shifting process of an automatic
transmission. These types of shifting sequences only slightly
restrain the performance level regarding various requirements so
that, in the end, the shifting processes is optimally adapted to
the respective conditions or else optimally short and comfortable
shifting sequences are to be obtained.
[0012] Accordingly, the invention proceeds from a method for
controlling an automatic transmission in which a starting clutch
and/or a clutch coupling and/or transmission elements for the
selection, as well as the engagement and the disengagement of the
gear steps determined as a function of the respectively existing
variables representing the driving situation as well as the wish of
the driver can be activated by actuators which are controlled by a
control and regulation device.
[0013] The following operation steps are provided as a solution to
the proposed problem in accordance with an initial embodiment:
[0014] recording of the interacting input variables of the shifting
operation, [0015] normalizing the input quantities to standard
input variables, [0016] weighting of the standardized input
variables with weighting factors, [0017] summarization of the
standardized and weighted input variables, [0018] summarization
and/or multiplication of the standardized and weighted input
variables into an intermediate variable, [0019] classification of
the intermediate variable in one or more specific ranges of values
which, in each case, represent a specific shifting sequence, [0020]
implementation of the shifting operation through recognition of the
actuator with the assistance of the acquired type of shifting
sequence of allocated actuator control variables and/or regulation
algorithms.
[0021] Through this course of action it is assured that the
actuators, for clutch activation and/or for the selection and
shifting operations, are controlled and/or regulated as a function
of the variables which depend not only on the driving situation or
the performance desires of the operator but which, moreover, take
into consideration the type of vehicle as well as its type of use.
In this way, this method can be utilized as a program module for
various clutch control mechanisms in various automatic
transmissions.
[0022] The following procedural steps are provided in accordance
with a second embodiment of the method: [0023] recording of the
interacting input variables of the shifting operation, [0024]
normalizing the input quantities into standard input variables,
[0025] weighting of the standardized input variables with weighting
factors, [0026] summarization of the standardized and weighted
input variables, [0027] summarization and/or multiplication of the
norms and weighted input variables into intermediate variables,
[0028] utilization of the intermediate variables as variation
factors, whose actuator control variables and/or regulator
algorithms is associated with at least one of the actuators, [0029]
implementation of the shifting operation through recognition of at
least one of the actuators with the assistance of variation factors
of adapted actuator control variables and/or regulation
algorithms.
[0030] This method also possesses the same advantages as the first
mentioned embodiment of the method. Nonetheless, here the mentioned
intermediate variables are directly associated with the actuator
control variables and/or the regulation algorithms, owing to which
storage capacity and, if need be, a calculation time in a clutch
control mechanism is also optimized.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] The invention will now be described, by way of example, with
reference to the accompanying drawings in which:
[0032] FIG. 1 illustrates a schematic flow-diagram for a data
processing program of a transmission control mechanism in
accordance with a first embodiment of the method, and
[0033] FIG. 2 provides an illustration, as in FIG. 2, but of a
second embodiment of the method.
DETAILED DESCRIPTION OF THE INVENTION
[0034] As FIG. 1 and FIG. 2 illustrate, a large number of driving
situation-relevant variables A, B, C, D, X are available as input
variables 1 during operation of a program loop of a transmission
control program configured in accordance with the invention.
[0035] For example, the accelerator adjustment angle, the
activation situation with reference to a kick-down-switch of an
accelerator, the brake activation signal for an activation state of
the service brake of the motor vehicle, the vehicle speed or
variables equivalent to it, the motor vehicle's longitudinal
acceleration, the vehicle's lateral acceleration driving
resistance, the gradient angle of the roadway, the current gear
being utilized, the target gear for the present driving condition,
the current engine torque of the vehicle gearbox and the clutch
temperature, as an indicator of the thermal stress conditions of
the clutch, are used as input variables 1, either additively or
alternatively, for both method embodiments of the invention as
driving situation characteristic variables. The concomitant
evaluation of the current motor vehicle mass is determined to be an
advantageous parameter for the status of the vehicle.
[0036] The input variables 1 are calculated, either directly by way
of sensors in an inherently known manner or from auxiliary measured
variables, or measured directly. Therefore, it is known how to
determine the traveling speed, for example, from the transmission
output rotational speed.
[0037] The values of the input variables 1 are then standardized at
calculation step 2 whereby the input variable is divided by a
respectively allocated or predetermined maximum value. In FIGS. 1
and 2, the respective calculation step 2 is indicated by the label
"Norm".
[0038] Subsequently, according to both method embodiments, the
values of the standardized input variables are respectively
multiplied by a preferred individual weighting factor 3 ("Factor")
which is shown in the both Figures at the allocated multiplication
step 4.
[0039] By the weighting factors 3 it is a matter of characterizing
variables, such as the type of motor vehicle, the type of
transmission, the performance characteristics of the drive motor
and/or the construction of the drive train. The characterizing
variable of the drive train construction reflects whether the
vehicle is front-wheel drive or rear-wheel drive or is equipped
with all-wheel drive.
[0040] Through weighting factors 3, the above mentioned
standardized initial variable is weighted in such a way that the
significance of the individual input variables 1 can be evaluated,
possibly overemphasized or moderately or even largely neglected,
for realization of the quickest possible shift, for example, or
possibly for the most comfortable shifting operation.
[0041] For this purpose, it is provided that the weighting factors
3 can also allow for whether the automatic transmission is being
used in a passenger motor vehicle, in a truck or in some other
commercial vehicle. According to a further refinement of the
invention, it is determined to be advantageous if the weighting
factors 3 also characterize whether the commercial vehicle is
constructed as a long distance truck, a city delivery vehicle, a
travel bus or a cross-country vehicle.
[0042] Subsequently, the standardized and weighting values of the
input variables 1 are added, in accordance with a first method
embodiment represented in FIG. 1 at addition step 5 of each program
loop, into an intermediate variable 6 which is then fed to a
classification stage 8. At the classification stage 8, the
intermediate value 6, calculated as described, is allocated one of
several predetermined classification ranges stored in a
classification range memory 7 ("Range"). In the classification
range memory 7, a shifting sequence type 9 is assigned to each of
these classification ranges so that the initial value of the
classification step 8 is one of several shifting sequence
types.
[0043] The limits of the classification ranges, for determination
of the shifting sequence 9, are preferably chosen depending on type
of the vehicle, the transmission type, the performance
characteristics of the drive motor and/or the construction of the
drive train.
[0044] As shown in FIG. 2, the standardized and the weighting
values of input variables 1 can be multiplied by one another, at
the multiplication step, to form the intermediate variable 6.
[0045] Not shown, but likewise being part of the invention, is a
third embodiment in accordance with which the standardized and the
weighted values of the input variables 1 can be multiplied, added
to or subtracted from each other.
[0046] In accordance with method variations defined by independent
claim 1, the respective shifting sequence types 9 are assigned
actuator control variables and/or regulation algorithms with the
assistance of which the actuator of the transmission and/or the
clutch are actuated and the gear ratio change sequence is
achieved.
[0047] Following determination of the shifting sequence type 9,
operation of the program loop, shown in accordance with FIG. 1 and
FIG. 2, is ended upon reaching sequence section 10, so that with a
renewed accommodation of the evaluation of the input variables 1, a
newly initiated gear ratio change process can be continued or can
be altered with respect to shifting comfort and/or the duration of
the shifting operation.
[0048] In accordance with the second embodiment, it can be provided
that the intermediate variable 6 is utilized as a discrete
variation factor, which is linked with actuator control variables
and/or control algorithms for activation actuation of at least one
of the actuators such that the shifting operation occurs with the
activation of at least one actuator as well.
[0049] Such linking of the intermediate variable 6 in the sense of
a change factor can, for example, run such that a variable
influencing the gradient of an actuator activation speed is
directly changed so that a clutch engaging process can possibly
proceed more rapidly, or more slowly, following a mathematical
function.
[0050] It is, however, possible that these intermediate values act
in the sense as changing factors that a second of two shift valves
are opened with which the aforementioned activation speed is
constantly increased, for example, in relation to a previous
value.
REFERENCE NUMERALS
[0051] 1 input variables A, B, C, D, and X [0052] 2 standardization
of the input values [0053] 3 weighting factor [0054] 4
multiplication step [0055] 5 addition step [0056] 6 intermediate
value [0057] 7 classification range memory [0058] 8 classification
stage [0059] 9 shift type [0060] 10 end of program loop [0061] 11
multiplication step
* * * * *